A power supply device has been known which includes a primary power storage element, a plurality of secondary power storage elements, and a plurality of voltage conversion circuits (regulators) provided respectively between the plurality of secondary power storage elements and a plurality of load circuits. Power generated by a power generation element is preferentially charged to the primary power storage element, the electrical charge of the power is distributed to the secondary power storage elements, and thus, high-speed activation and supply of a desired voltage to each of the load circuits are both achieved.
In this power supply device, the number of components (the circuit scale) and the cost are increased because the voltage conversion circuits need to be provided for the respective load circuits. In addition, when a plurality of types of the power generation elements are provided, the voltage conversion circuits need to be provided also for respective output sides of the power generation elements. That is, both the power generation element side and the load circuit side need the voltage conversion circuits by the number of the power generation elements and the number of the load circuits. For this reason, the number of components (the circuit scale) and the cost are multiplied.